The present invention relates to tools for use with mineral winning machines, especially ploughs, and particularly, but not solely, to tools for coal mining.
In high performance underground coal winning it is well known to utilize a plough which is moved back and forth along a coal face to strip coal from the face with the aid of cutter tools. The conventional cutters are usually made from a block of metal to which a hard-metal blade or attachment forming a cutting region is fixed. Usually the cutters are detachably mounted to holders permitting easy replacement of the cutters. It is also known to utilize high pressure water jets to win coal i.e. the so-called hydraulic winning. German Patent specification No. 2307413 describes a coal winning machine provided with nozzles discharging high pressure water for winning coal by the hydraulic method.
A general object of this invention is to provide improved tools and winning machines which will provide high yields with maximum durability.